Remote multi-position information gathering system and method

ABSTRACT

A technique for gathering specific information from various remote locations, especially fluorimetric information characteristic of particular materials at the various locations is disclosed herein. This technique uses a single source of light disposed at still a different, central location and an overall optical network including an arrangement of optical fibers cooperating with the light source for directing individual light beams into the different information bearing locations. The incoming light beams result in corresponding displays of light, e.g., fluorescent light, containing the information to be obtained. The optical network cooperates with these light displays at the various locations for directing outgoing light beams containing the same information as their cooperating displays from these locations to the central location. Each of these outgoing beams is applied to a detection arrangement, e.g., a fluorescence spectroscope, for retrieving the information contained thereby.

The Government has rights in this invention pursuant to Contract No.W-7405-ENG-48 awarded by the U.S. Department of Energy.

This is a continuation, of application Ser. No. 194,684 filed Oct. 6,1980.

The present invention relates generally to techniques for gathering orobtaining information at one or more remote locations and moreparticularly to a specific technique for obtaining from one or moreremote locations fluorimetric information, that is, fluorescent lightemanating from and characteristic of particular materials at theselocations, without utilizing entirely separate information gatheringapparatus located at each of the information bearing locations.

Modern technology is dependent on analytical monitoring and control aswell as information gathering processes. However, in many cases, theanalysis or information gathering process must be done from a distance,for example, where the data or information is located at an undergroundnuclear waste-disposal site, inside a nuclear reactor, at the workingzone of a coal-liquefication reactor, or like environments which aremuch too hostile for most in situ analytical devices. In this regard, itshould be noted that the problem is not limited to industry. In thefield of research and development the disadvantages of putting anexpensive analytical instrument into an extremely hostile environmentsuch as a highly radioactive hot cell, or the like must be weighedagainst the need for the information to be obtained thereby.

Heretofore, the various problems just described resulted in thedevelopment of especially ruggedized but extremely expensive instrumentsor, when possible, of equally rugged and expensive sampling systemscapable of collecting representative samples for delivery to theinstrument, without alteration. This is especially impractical when alarge number of these instruments or sampling systems are required whenmonitoring and/or information gathering is to take place at about thesame time at a number of remote locations.

In view of the foregoing, one object of the present invention is toprovide an uncomplicated, reliable and yet economical technique forobtaining specific information from remote locations, especially hostilelocations or at substantial distances (e.g. 1000 feet) where requiredand without requiring ruggedized instruments or equally rugged samplingsystems at the measurement site.

A more particular object of the present invention is to provide amulti-location information gathering technique of the type just recitedin which the primary instrumentation is common to all of the informationbearing locations and all of these locations are interrogatedsubstantially simultaneously.

Another particular object of the present invention is to provide amulti-location information gathering techhique in which its primaryinstrumentation and the various information bearing locations areinterconnected optically so as to make the technique especially suitablefor gathering information located in hostile environments.

A further particular object of the present invention is to provide anuncomplicated, reliable and yet economical technique for obtaining froma given location or substantially simultaneously from a number of givenlocations information in the form of measurements of fluorescent lightemanating from and characteristic of particular material at theinformation bearing locations and also a technique which utilizes asingle fluorescence spectroscope even though more than one informationbearing location may be involved and even though these locations may bein relatively hostile environments.

Still a further particular object of the present invention is tooptically couple the fluorescent spectroscope just recited to theinformation bearing locations involved utilizing the long range opticalgiver technology developed by the communications industry.

Yet a further particular object of the present invention is to provideuncomplicated, reliable and yet economical light focusing and collectingdevices for use in the technique last recited, while maintaining thenormal signal gathering efficiency of fluorescence spectroscopy despitethe severe optical constraints of interfacing to and transmitting thelight through low attenuation fiber optic types.

As will be seen hereinafter, the overall information gathering techniquedisclosed herein is one which utilizes a single source of light providedat a location away from the information bearing location or locations.Means including an arrangement of optical fibers and the light sourcecooperate to direct individual beams of light into the variousinformation bearing locations for causing the production of lightsignals which can be measured and which contain the information to beobtained at these latter locations. This "light signal" can be a resultof fluoresence, light scattering, reflectance or other phenomena whichcauses light (both in the visible and invisible spectrum) to bere-emitted or produced as a result of the initiating beam. The opticalmeans including its arrangement of fibers and coupling devices at theinstrument as well as sampling devices at the distal end cooperate todirect outgoing beams of light towards locations to be measured, andreturn the remote signals to a central location, preferably the samelocation as the light source.

In the specific embodiments disclosed herein, the information to beobtained results from the fluorescence of specific material at each ofthe various information bearing locations. The incoming light beams areused at least in part to cause the material to fluoresce and a singlefluorescence spectroscope serves to detect and retrieve the informationcontained in the return beams produced as a result of the samplefluorescence at the remote end.

The overall information gathering technique disclosed herein will bediscussed in more detail hereinafter in conjunction with the drawingwherein:

FIG. 1 diagrammatically illustrates a system for obtaining fluorimetricinformation from a single remote location in accordance with the presentinvention, using separate fibers for sending out the exciting light andreceiving back the excited fluorescence, scattering, or reflectancesignal;

FIG. 2 is an enlarged axial sectional view illustrating one end sectionof an optical fiber which may be used with the system of the generaltype illustrated in FIG. 1 and a light focusing and gathering devicedesigned for such a system;

FIG. 3A diagrammatically illustrates a system similar to FIG. 1 but onewhich utilizes a common (single) optical fiber;

FIG. 3B diagrammatically illustrates a beam splitter arrangementespecially suitable for use in the system of FIG. 3A;

FIG. 3C diagrammatically illustrates another beam splitter arrangementsuitable for use in the system of FIG. 3A;

FIG. 4A diagrammatically illustrates the optical characteristics at theend of an optical fiber of the general type used in the systems of FIGS.1 and 3A;

FIG. 4B is an enlarged axial view, in section, illustrating an endsegment of an optical fiber which may be used with the systems of FIGS.1 and 3A and a light focusing and gathering device for use with suchsystems and designed in accordance with the second embodiment;

FIG. 4C is a view similar to FIG. 4B (and FIG. 2) but illustrating stillanother embodiment of a light focusing and gathering device particularysuitable for the system shown in FIG. 3A; and

FIG. 5 is a diagrammatic illustration, in block diagram, of a system forobtaining fluorimetric information from one or a number of remotelocations (substantially simultaneously) and in accordance with apreferred embodiment of the present invention.

Turning now to the drawing, attention is first directed to FIG. 1 which,as stated above, diagrammatically illustrates a system for obtainingspecific fluorimetric information from a given location. The system isgenerally indicated at 10 and a particular information bearing locationwhich may or may not be a hostile environment of the type recited aboveis indicated by dotted lines at 12. As will be discussed in more detailbelow, system 10 includes a source of light 14, which must be capable ofbeing focused efficiently to the small diameter and acceptance angle ofa low attenuation communication fiber, an overall optical network 16including an arrangement of communication grade (low attenuation)optical fibers, and a fluorescent spectroscope 18. Light from source 14is converted into a beam which by means of the arrangement of opticalfibers, for example a single fiber 20, directs the light beam intolocation 12 and onto a section of material 22 for causing the latter tofluoresce in a way which is characteristic of the material. Network 16including its arrangement of optical fibers, for example a single fiber24 comprising part of the arrangement, collects part of the fluorescentsignal into a returning beam of light containing the same information asthe fluorescence to spectroscope 18. While not shown in FIG. 1, thesource of light 14 and spectroscope 18 are preferably positioned at thesame location. In addition, suitable data processing equipment 26 may beprovided for acting on the information retrieved by the spectroscope 18for subsequent processing purposes.

Referring now to the specific components making up overall system 10 inmore detail, attention is first directed to light source 14. The lightsource may be of a suitable type which produces a beam of light 30compatable with material 22 and fluorescent spectroscope 18, that is, abeam capable of causing material 22 to fluoresce in a way which ischaracteristic of the particular information to be sought from material22. In a preferred embodiment, the light source is a laser apparatus andthe beam 30 is monochromic light displaying a wavelength in theultraviolet-visible-near infrared region.

The overall optical network 16 including its arrangement of opticalfibers may be of any suitable type so long as it functions in the mannerdescribed above. In the embodiment illustrated in FIG. 1, this networkincludes an emission filter 32 and lens 34. The emission filter servesto eliminate laser cavity emission from the beam so as to confine thelatter to a single wavelength. Lens 34 is appropriately located in beam30 behind filter 32 and in front of one end of optical fiber 20 forfocusing the beam onto the end of the optical fiber for transmissiontherethrough with minimum entry losses. The optical fiber itself ispreferably one which is presently available in the communicationsindustry for propagating a light beam, having a small cross-section, forexample on the order of a few hundred microns, over many hundreds ofyards with only slight attenuation. The specific optical fiber is onewhich can be readily purchased by designating it as the type used in thetelephone system. Optical fiber 24 is preferably of the same type. Inthe embodiment illustrated, these two optical fibers form the entirearrangement of optical fibers comprising part of overall optical network16. However, as will be discussed hereinafter, the optical fiberarrangement may be formed in a number of different ways.

In addition to emission filter 32, lens 34 and the two optical fibersjust mentioned, overall optical network 16 includes a second lens 36,specifically a collector lens for capturing and straightening theoutgoing beam generally indicated at 38, a wavelength filter 40 servingto filter out unwanted light from the beam. In additon to thesecomponents and those described above, overall optical network 16includes suitable means cooperating with the end of optical fiber 20 atlocation 12 for focusing incoming beam 30 onto material 22 to producefluorescence and suitable means cooperating with the adjacent end ofoptical fiber 24 for collecting light from the fluorescent display so asto form outgoing beam 38. Each of these latter means may be of anysuitable type to be discussed below with respect to FIGS. 3A-3C.However, one such arrangement which can be used both as a focusing meansand as a light collecting means is illustrated in FIG. 2 and generallydesignated by the reference numeral 44. As seen in this figure,arrangement 44 is in the form of a spherical lens, specifically asapphire ball in a preferred embodiment. FIG. 2 also shows an endsection of optical fiber 20 in detail. As seen there, this fiberincludes a single light transmitting core at 46 concentrically disposedinside an outer cladding 48 which is bonded inside a glass tube 50 bymeans of suitable bonding cement located concentrically therebetween.The outermost glass tube includes an end section 54 which extends beyondthe central core and cladding material for fixedly supporting lens 44 ina concentrically disposed position by suitable bonding cement generallyindicated at 56. As a focusing device, lens 44 acts as a collector forincoming beam 30 (indicated by dotted lines) on one side and focuses thecollection light to a point at material 22 on its opposite side. As acollector, the lens collects the light resulting from the fluorescentdisplay on one side and focuses its collected light onto the end of thecore 46 on its opposite side to provide outgoing beam 38 (indicated bydotted lines).

Overall information gathering system 10 has been described above ashaving two optical fibers, incoming fiber 20 and outgoing fiber 24. Itis, however, preferable to provide an arrangement of optical fibers inwhich one fiber is common to both the incoming beam and the outgoingbeam. For example, incoming beam 30 could be directed into location 12in the same manner as described above. However, instead of utilizing asecond, separate optical fiber 24 and associated collector lens, theoptical fiber 20 and its associated focusing lens 44 could be used tocollect the light from the fluorescent signal as will be discussed inmore detail below with respect to FIGS. 3A-3C. This collected lightcould be directed back into and through optical fiber 20 toward source14. However, a suitable beam splitter, for example those to be discussedspecifically in FIGS. 3B and 3C (indicated by dotted lines at 58 inFIG. 1) would be provided for diverting this outgoing beam along aseparate path defined by a separate optical fiber 60 which couldotherwise be identical to previously recited optical fiber 24, butwithout a collector lens. The opposite end of this latter optical fiberwould be coupled to lens 36 in the same manner as optical fiber 24. Thisoverall configuration of course assumes that the outgoing beam of lightis produced at a wavelength sufficiently different from the incomingbeam so that the two can be separated.

Having described system 10 and arrangement 44, attention is directed amodified system 10' which requires only a single fiber for directing thebeam of light to a remote control location and for collecting theresultant light signal thereat, as briefly discussed above. This lattersystem is illustrated in FIG. 3A and includes a light source capable offocusing on a very small spot, e.g. the laser 14 illustrated in FIG. 1or possibly an ultrahigh pressure mercury arc lamp such as used influorescence microscopy. A beam from this source is acted on by anilluminator lens 25 and thereafter passes onto a single fiberbidirectional coupler 27. A readily provided fiber optics connector 29serves to connect one end of a long distance communication optics fiber31 to the coupler. The fiber's other end is connected to another fiber31 by a similar connector 29. The distal end of the second fiber 31includes an arrangement 44 as discussed in FIG. 2 or like arrangementserving both to illuminate the sample under test and for collecting thelight signal resulting therefrom. This light signal is returned by thefibers 31 to coupler 27 which redirects the collected light beam throughthe collector lens 36 and thereafter to the fluorescent spectrometer 18.

Two examples of couplers (which also serve as beam splitters) areillustrated in FIGS. 3B and 3C generally and are designated by thereference numerals 27' and 27", respectively. The beam splitter 27'cooperates with the previously recited illuminator lens 25, connector 27and collector lens 36 along with a dichroic beam splitter or anintensity splitting beam splitter. The former must be changed for eachset of fluorescence excitation and emission wavelengths used while thelatter one does not but does impose a heavy penalty in signal levels.The arrangement 27" is a perforated mirror in order to geometricallyseparate the low convergence illumination beam (the incoming beam) andthe more divergent return beam (which is limited only by the fibernumerical aperture).

Returning briefly to FIG. 2, attention is again directed to thecombination beam focusing and collection arrangement 44. In describingthis arrangement above, it was assumed that the material 22 beinganalyzed emits sufficient fluorescent light to provide a strong enoughoutgoing beam 38 to be analyzed. It was also assumed that there is adesire to collect all of the fluorescent light emitted by the material.In some cases, material 22 may not be of a type which by itself emits astrong enough fluorescent signal to be analyzed. In other cases,material 22 may include ingredients which fluoresce unwanted light. Toeliminate these problems, lens 44 can be provided with an outer coatingwhich combines with the incoming beam to cause the material 22 to give afluorescent signal to a greater degree. For example, a solution ofrubrene in polystyrene plastic coating could be provided when material22 is iodine, which extinguishes the rubrene fluorescence. In any event,once material 22 is selected, the coating which will enhancefluorescence can be readily selected.

In order to more fully understand the way in which a single fiber can beused to direct a beam of light into a particular area under evaluationwhile at the same time serving to collect a resultant light signalthereform and cause or aid in causing the production of a suitable lightsignal, attention is briefly directed to FIGS. 4A to 4C. FIG. 4Aillustrates an optical fiber 20' similar to previously described fiber20 but without the outer surface 50. Rather as seen in FIG. 4A., fiber20' includes a fiber core 46' and outer cladding 52' bonded together bysuitable means 48'. FIG. 4A specifically illustrates the way in whichthe fiber 20' distributes and collects light without the aid ofarrangements such as the arrangement 44 illustrated in FIG. 2. In FIG.4A, the possible light which might result at the end of the fiber can bedivided into three groups, the central cone shaped group designated atV1, the larger cone shaped area described at V2 and the area V3 outsidethe larger cone shaped area. All of the light emitted backwards towardsthe fiber core from within the volume V1 will be collected by the fiber.On the other hand, only part of the light emitted backwards towards thefiber core from within the volume V2 (excluding the volume V1) will becollected by the fiber. Finally, none of the light within the areadesignated at V3 will be collected by the fiber. The converse of each ofthese results is equally true, that is, light from the fiber willilluminate the entire volume V1, only part of the volume V2 and none ofthe volume V3.

An arrangement such as that illustrated in FIG. 4A is equivalent to asample cell 0.22-0.8×fiber diameter (in depth), for practical values ofthe fiber numerical aperture. In order to increase the light signal,larger fiber core diameters could be used but soon become too costly andunwieldly, since the low attenuation communication fibers are rathersmall. Lenses can however be used to increase the apparent fiberdiameter, but should be high in index to avoid strong performancealternations produced by sample refractive index changes.

A much more practical embodiment to use for directing a beam of lightinto a given area and for collecting the resultant light signal is thepreviously described arrangement 44 illustrated in FIG. 2. However, whenthe sample is not fluorescent, or when its fluorescence is not selectiveenough to derive exclusively from the species being sought, specificfluorescent reagents, fluorescense extinction reagents or extractionreagents can be used. These will create a fluoresce signal from thesample, or make the one they produce more selective. These reagents caneasily be applied as a layer on top of the end face of the fiber core.The reagent must be a reversible one, in equilibrium with the samplemedium, so that it does not get consumed and is yet able to reflectsample concentration fluctuations. It must also be stable and insoluable(or somehow chemically attached to the surface). For a lens system, thereagent location would have to be in and spaced in front of the lens,requiring a separate holder. To put it on the lens end face would besimpler, but to provide the focus there would require a lens indexgreater than two times the medium, which is extremely difficult givenmaterial limitations in the wavelength region discussed previously.

A different lens type, specifically the commercial selfor (NipponElectric Company) rod lens, has a focus on its end surface, and can beused here to advantage. This lens is based on a rod with a parabolicradial distribution of refractive indices and a preselected length. Sucha lens is illustrated in FIG. 4B at 44' in combination with the fiber20" which is identical to previously illustrated fiber 20 and includesthe same components including the same extended end. In this regard,note that the lens 44' is fixedly contained in the extension 54 inspaced relationship with the fiber core itself indicated at 46. In thisway, the reagent can be located on the flat end surface of the rod lens.

The limited travel of the illumination beam in the sample before itsspreading renders most of the generated fluorescence non-collectible bythe fiber limits the methods total sensitivity. This can be avoided bycontaining the beam spread in a glass capillary as illustrated in FIG.4C. There, the arrangement 44 is shown in combination with a glasscapillary 80. Suitable means generally illustrated at 82 are providedfor mechanically maintaining the capillary in concentric alignment witharrangement 44.

Having described overall information gathering system 10 in detail, itshould be apparent that this system has been designed for obtainingspecific fluorimetric information at only one location. Because of therelatively high cost of fluorimetric analytical equipment, specificallya fluorescence spectroscope and laser light sources, it would be highlydesirable to use a single laser and spectroscope to obtain fluorimetricinformation from a number of different locations substantiallysimultaneously, that is, in sufficiently rapid succession to make itunnecessary to physically move the entire equipment to the variouslocations. The system for achieving this is illustrated in FIG. 5 and isgenerally indicated at 62. As seen there, the same laser 14 may bebrought remotely to the various information bearing locations forproducing previously recited beam 30. The same emission filter 32, lens34 and beam splitter 58 described with respect to FIG. 1 can be providedfor the same reasons described there.

As seen in FIG. 5, beam 30 is applied from the beam splitter to acooperating end of an inlet optical fiber diagrammatically illustratedat 64. The inlet fiber may be identical in construction to previouslydescribed optical fiber 20. While not shown, the beam splitter itselfincludes an optical lens or like means for focusing beam 30 onto theadjacent end of fiber 64 whereby to assure that the entire beam entersthe inlet fiber or the beam splitter may be like those shown in FIGS. 3Band 3C. The opposite end of this fiber is optically coupled, for exampleby means of a fiber connector and/or suitable lens, to the input of astar coupler 66. This latter device serves to alternatively direct beam30 through a number of different outlets utilizing a combination ofreflectors (e.g., mirrors) including at least one which is movablebetween a number of different positions. This movement can take placemanually or automatic means can be readily provided. One such device ismanufactured by Math Associates under the name of Two Part OpticalCoupler. At each outlet of star coupler 66 is one end of a main orprimary (long) optical fiber 68 which is coupled to its associatedoutlet by suitable optical means, for example a lens, so that beam 30may be alternatively directed into any one of the longer fibers. Overallsystem 62 is shown including four primary fibers 68 in FIG. 3 andtherefore star coupler 66 includes at least four outlets.

All of the components making up overall system 10 thus far described,that is, laser 14, emission filter 32, lens 34, beam splitter 58, inletfiber 64, star coupler 66 and the coupled ends of primary fibers 68 arepreferably located at the same central location. The various primaryfibers extend from this location to the various information bearinglocations. At each of these latter locations an outlet fiber 70 isoptically coupled at one end to the adjacent end of an associatedprimary fiber by suitable means, for example by an appropriate lens suchthat the beam 30 traveling through the primary fiber enters the outletfiber. The other end of each outlet fiber includes what is referred toas an optrode for bringing its associated incoming beam 30 onto acorresponding material 22 and for collecting the light from thefluorescent display resulting therefrom. Outlet fibers 70 can beconstructed in the same manner as previously described optical fibers 20and the optrodes can be identical to and connected in the same manner aspreviously described focusing/collecting arrangement 44 or the otherarrangements shown in FIG. 4.

The light collected by each optrode 44 in system 62 produces acorresponding outgoing beam 38, as in system 10. Each of these latterbeams passes through outlet fiber 70 in the opposite direction as beam30 and thereafter through its associated primary fiber 68, again in theopposite direction as beam 30. The various beams 38 are thereafteralternatively directed into star coupler 66 (through associated outletsof the latter) and from the star coupler into the single inlet fiber 64towards beam splitter 58. After leaving inlet fiber 64 in the oppositedirection as beam 30, beam 38 is directed through beam splitter 58 to acollector lens 36 which may be identical to the previously describedcollector lens comprising part of system 10. From the collector lens,the beam passes through a wavelength filter 40 and spatial filter 42 asin system 10 and, if desired, still another wavelength filter 40 andfinally into spectroscope 18. The information from the spectroscope maybe applied to appropriate data processing equipment 26 as in system 10.

From the foregoing, it should be apparent that a number of differentremote locations which may or may not be in hostile environments can besubstantially simultaneously monitored for fluorimetric informationusing a single laser and only one fluorescence spectroscope which aregenerally the most expensive components making up the overall system. Infact, in system 62, the only duplication of components associated withthe various information bearing locations are the primary fibers, outletfibers and optrodes.

It should also be apparent that this multi-position technique is equallyapplicable for obtaining from various different locations informationother than fluorimetric information. More specifically, a system similarto system 62 could be provided for monitoring temperature or other typesof information which can be obtained optically, that is, by means of anincoming beam and an outgoing beam. For example, in the case oftemperature, the incoming beam is passed into the area being monitoredthrough an appropriate sensor such as the one described in U.S. Pat. No.4,179,927. The outgoing beam is characteristic of the temperature at thesensor, as described in the patent just recited. In other words, theincoming beam in combination with the sensor would provide a signal inthe sensor (e.g. the incoming beam itself) and this signal by means ofreflection forms the basis for an outgoing beam directed back out of thesensor and towards its associated detector as described in the U.S. Pat.No. 4,179,927. This is only one possible information gathering approachwhich could be used in lieu of or in combination with the gathering offluorimetric information in overall system 62. In the case oftemperature sensing or similar situations wherein the incoming andoutgoing beams may have common wavelengths, it may in special cases benecessary to use separate optical networks for carrying the incoming andoutgoing beams to reduce the background. However, the same laser anddetector system could be readily provided as in system 62.

What is claimed is:
 1. A system for obtaining specific information fromdifferent information bearing locations comprising: means positioned ina location remote from said different locations for providing a sourceof light displaying a given wavelength characteristic; optical meansincluding an arrangement of optical fibers cooperating with said lightsource for directing individual light beams into said differentlocations, said arrangement of fibers including single fibers at saiddifferent locations, respectively, for directing said individual beamstherein; individual means positioned at each of said different locationsand responsive to an incoming one of said individual light beams from anassociated one of said single fibers for providing a display of lightcontaining the information to be obtained at that location, said displayof light displaying a wavelength characteristic different than saidgiven wavelength characteristic; said optical means cooperating with thelight displays at said different locations for directing outgoing beamsof light from said different locations to a single location remote fromsaid different locations at least initially along said single fibers,each of said outgoing beams containing the same information as itscooperating light display at the wavelength characteristic of thelatter; and means positioned at said single location for detecting saidoutgoing beams whereby to retrieve said information contained therein;each of said single fibers including one end which is located at itsinformation bearing location in close proximity to said material, saidfiber serving to carry both said incoming and outgoing beams, andwherein said optical means includes a spherical lens cooperating witheach of the one ends of said single fibers for focusing said incomingbeam onto its material and for collecting light from said light displayfor producing said outgoing beams.
 2. A system according to claim 1wherein said light source and detecting means are positioned at a commonlocation remote from said different locations.
 3. A system according toclaim 2 including means located at said common location for retrievingthe information contained in said outgoing beams.
 4. A system accordingto claim 1 wherein the light display providing means in one of saiddifferent locations includes a material which upon impingement by anincoming one of said individual beams of light fluoresces in a way whichis characteristic of said material for providing a display of lightcontaining information characteristic of said material.
 5. A systemaccording to claim 4 wherein the light display providing means in eachof said different locations includes a material which upon impingementby an incoming one of said individual beams of light fluoresces in a waywhich is characteristic of said material for providing a display oflight containing information characteristic of the particular material.6. A system according to claim 1 wherein each of said spherical lensesincludes means for aiding said material to cause the material tofluoresce.
 7. A system according to claim 1 wherein each of saidspherical lenses includes means for preventing certain wavelength lightfrom being collected.
 8. A system according to claim 1 wherein saidarrangement of optical fibers includes means for producing saidindividual incoming beams alternative to one another whereby saidoutgoing beams are provided alternative to one another.
 9. A system forobtaining from each of a number of different given locations informationin the form of a display of fluorescent light having a given wavelengthcharacteristic and emanating from and characteristic of a particularmaterial at that location, said system comprising: means positioned in acentral location remote from said given locations for providing a singlesource of light having a wavelength characteristic different than thegiven wavelength characteristics; an optical network including anarrangement of optical fibers cooperating with said light source fordirecting individual light beams into said different given locations,said network including optical fiber means for directing an initial beamof light from said light source to a fixed point spaced therefrom andfor directing said individual beams of light from said point to saidgiven locations, means for causing said initial beam of light to providealternatively any given one of said individual beams; means located ateach of said given locations in close proximity to the fluorescent lightemanating material thereat and cooperating with said fiber means forfocusing the individual beam of light directed into its given area ontothe adjacent material so as to cause the latter to fluoresce and therebyproduce a display of light characteristic of said material, saidfocusing means also serving to collect at least a portion of the lightfrom said display and direct the collected light in the form of acorresponding outgoing light beam from the given area to said fixedpoint, all of said outgoing beams containing the same information astheir cooperating light displays; said optical network including opticalfiber means for directing said outgoing beams to said central location;and means positioned at said central location for detecting saidoutgoing beams whereby to retrieve said information contained thereby;said optical fiber means including a plurality of individual opticalfibers, equal in number to the number of said given locations, each ofsaid optical fibers extending from said fixed point to an associated oneof said given locations, and wherein said focusing means includes aplurality of spherical lenses equal in number to said individual fibers,each of said lenses having focal points on opposite sides thereof andbeing fixedly mounted adjacent an end of an associated individual fiberat its associated given location such that said last-mentioned end is atone focal point and the light display at the opposite focal point.
 10. Asystem for obtaining specific information from a particular samplesubstance of the type capable of interacting directly with a reversible,nonconsumable second substance when the latter is fluorescing such thatas a result of said direct interaction, said second substance fluorescesin a way which is characteristic of said information, said systemcomprising: optical fiber means having a light collecting end andincluding said second substance carried by said light collecting end;means for causing said second substance to fluoresce at a locationsufficiently close to said sample substance so as to provide said directinteraction and thereby cause said second substance to producefluorescent light characteristics of said information; means includingsaid optical fiber means for collecting at least some of saidfluorescent light; and means for retrieving said information from thecollected light.
 11. A system according to claim 10 wherein said samplesubstance is iodine and said second substance is rubrene.
 12. A systemaccording to claim 10 wherein said optical fiber means includes an endsurface serving as said end and wherein said second substance ischemically bonded to said end surface.
 13. A method of obtainingspecific information from a particular sample substance of the typecapable of interacting directly with a reversible, nonconsumable secondsubstance when the latter is fluorescing such that as a result of saiddirect interaction said second substance fluoresces in a way which ischaracteristic of said information, said method comprising the steps of:carrying said second substance on the end of fiber optic means, causingsaid second substance to fluoresce by passing light through said fiberoptics means; positioning said sample substance sufficiently close tosaid second substance so as to provide said interaction and therebycause said second substance to produce fluorescent light characteristicof said information; collecting at least some of said fluorescent lightthrough said fiber optics means; and retrieving said information fromthe collected light.
 14. A method according to claim 13 wherein saidsample substance is iodine and said second substance is rubrene.
 15. Asystem for collecting fluorescent light containing specific informationcharacteristic of a particular sample substance which is capable offluorescing and for obtaining said specific information from said light,said system comprising: means for causing said sample substance tofluoresce at a particular location; means including a second substancefor interacting with said sample in a way which alters the sample'sfluorescent light emanating characteristics in a predetermined way,whereby the altered light contains said specific information; means forcollecting at least some of said altered fluorescent light, and meansfor retrieving said specific information from said collected light. 16.A system according to claim 15 wherein said means including said secondsubstance includes optical fiber means having end means serving as saidlight collecting means, said end means carrying said second substance.17. A system according to claim 16 wherein said end means includes lensmeans serving as said light collecting means.
 18. A system according toclaim 15 wherein said second substance interacts with said sample in away which causes the latter to fluoresce to a greater extent than wouldbe the case in the absence of said substance.
 19. A system according toclaim 15 wherein said second substance interacts with said sample in away which prevents certain fluorescent light from emanating from saidsample.
 20. A system according to claim 15 wherein said second substanceis from the group consisting of specific fluorescence productingreagents, fluorescence extinction reagents and/or fluorescenceextracting reagents.
 21. A system according to claim 20 wherein each ofsaid reagents is a reversible one, in equilibrium, with the samplestable and attached to the system so that it does not get lost orconsumed.
 22. A method of collecting fluorescent light containingspecific information characteristic of a particular sample substancewhich is capable of fluorescing and for obtaining said specificinformation from said light, said method comprising the steps of:causing said sample substance to fluoresce at a particular location;selecting a second reversible, nonconsumable substance and positioningit to interact directly with said sample in a way which alters thesample's fluorescent light emanating characteristics in a predeterminedway, whereby the altered light contains said specific information;collecting at least some of said altered fluorescent light; andretrieving said specific information from said collected light.
 23. Amethod of obtaining specific information characteristic of a particularsample substance from fluorescent light which contains said informationand which results form the interaction of said sample substance and asecond substance, one of which is capable of fluorescing, said methodcomprising the steps of: causing said substances to interact and therebyproduce said fluorescent light; collecting at least some of saidfluorescent light; and retrieving said specific information from saidcollected light.
 24. A system for obtaining specific information from aparticular sample substance of the type capable of interacting directlywith a reversible, nonconsumable second substance when the latter isfluorescing such that as a result of said direct interaction said secondsubstance fluoresces in a way which is characteristic of saidinformation, said system comprising: optical fiber means having a lightcollecting end surface and said second substance bonded directly to saidend surface of said optical fiber means; means for causing said secondsubstance to fluoresce at a location in contact with said samplesubstance so as to provide said direct interaction and thereby causesaid second substance to produce fluorescent light characteristic ofsaid information; means including said optical fiber means forcollecting some of said fluorescent light through said fiber means; andmeans of retrieving said information from the collected light.
 25. Asystem according to claim 24 wherein said second substance is chemicallybonded to said end surface.
 26. A system according to claim 25 whereinsaid optical fiber means includes a single optical fiber defining saidlight collecting end surface.
 27. A system for obtaining specificinformation from a particular sample substance of the type capable ofinteracting directly with a reversible, nonconsumable second substancewhich itself is capable of fluorescing such that, as a result of saiddirect interaction, said second substance fluoresces in a way which ischaracteristic of said information, said system comprising: meansincluding a single optical fiber having a light collecting end surfaceand said second substance bonded directly to said end surface; means forcausing said second substance to fluoresce at a location sufficientlyclose to said sample substance so as to provide said direct interactionand thereby cause said second substance to produce fluorescent lightcharacteristic of said information; means including said single fiberfor collecting some of said fluorescent light through said fiber; andmeans for retrieving said information from the collected light.
 28. Asystem according to claim 27 wherein said second substance is chemicallybonded to said light collecting end surfaces.
 29. A system forcollecting fluorescent light containing specific informationcharacteristic of a particular sample substance which is capable offluorescing and for obtaining said specific information from said light,said system comprising: means for causing said sample substance tofluoresce at a particular location; optical fiber means having a lightcollecting end surface and a reversible, nonconsumable second substancebonded directly to said surface for interacting directly with saidsample in a way which alters the sample's fluorescent light emanatingcharacteristics in a predetermined way, whereby the altered lightcontains said specific information; means including said fiber means forcollecting some of said altered fluorescent light through said fibermeans, and means for retrieving said specific information from saidcollected light.
 30. A system according to claim 29 wherein said secondsubstance is chemically bonded to said end surface.
 31. A systemaccording to claim 30 wherein said optical fiber means includes a singleoptical fiber defining said light collecting end surface.
 32. A methodof collecting fluorescent light containing specific informationcharacteristic of a particular sample substance which is capable offluorescing and for obtaining said specific information from said light,said method comprising the steps of: providing optical fiber meanshaving an end surface; directing a beam of light through said opticalfiber means and end surface and onto said sample substance for causingsaid sample substance to fluoresce at a particular location; selecting areversible, nonconsumable second substance and bonding said secondsubstance to the end surface of said fiber means; positioning saidsecond substance to interact directly with said sample in a way whichalters the sample's fluorescent light emanating characteristics in apredetermined way, whereby the altered light contains said specificinformation; collecting some of said altered fluorescent light throughsaid fiber means; and retrieving said specific information from saidcollected light.
 33. A method according to claim 32 wherein said secondsubstance is chemically bonded to said end surface.
 34. A methodaccording to claim 33 wherein said optical fiber means includes a singleoptical fiber defining said light collecting end surface.
 35. A methodof obtaining specific information characteristic of a particular samplesubstance from fluorescent light which contains said information andwhich results from the direct interaction of said sample substance and areversible, nonconsumable second substance, one of which is capable offluorescing, said method comprising the steps of: providing opticalfiber means having an end surface and bonding said second substancedirectly to said surface; directing light through said fiber means andend surface and onto the substance capable of fluorescing; causing saidsubstances to interact directly and thereby produce said fluorescentlight; collecting some of said fluorescent light through said fibermeans; and retrieving said specific information form said collect light.36. A method according to claim 35 wherein said second substance ischemically bonded to said end surface.
 37. A method according to claim36 wherein said optical fiber means includes a single optical fiberdefining said light collecting end surface.